The periodic table was developed in order to group and organize elements with similar physical and chemical properties. elements such as fluorine, chlorine, and iodine all are very reactive and only need one more electron to fill their outer shells. which of these best describes this family of elements? a) halogens b) noble gases c) alkali metals d) alkaline earth metals

Tara sees a commercial for a brand of pills that promise to boost energy and people perform better in work and school. as people in the commercial talk about how much better they feel when taking the pill, tara notices a message on the bottom of the screen that reads, "this pill is not approved by doctors and has not been tested in controlled experiments." what is the best conclusion that tara should make about the commercial? it is making scientific claims based on subjective observations. it is making scientific claims based on opinions instead of pseudoscientific facts. it is making pseudoscientific claims based on objective observations. it is making pseudoscientific claims based on opinions instead of scientific facts.

Beth’s hygrometer is reading a temperature of 30 c and a relative humidity of 65%. the humidity in the air is?

Veins have a much lower blood pressure than arteries. which of these prevents backflow of blood in veins? a. pressure applied by the heart b. one–way valves in veins c. thin muscular walls of veins